In the automotive industry, vehicle bodies are built using both aluminum and galvanized steel and assembled by welding including gas metal arc welding (“GMAW”) and gas tungsten arc welding (“GTAW”). These types of welds, GMAW and GTAW, typically require a large heat input.
Laser welding is a well-established joining process that exhibits significant performance benefits, e.g. minimal distortion, high speed and minimal heat-affected-zone (HAZ). However, in order for laser welding to yield a high performance joint, the two workpieces must fit together tightly and have a minimal gap; thus, requiring very tight tolerances in spatial location and orientation of the mounting surfaces.
When assembling the frame of an automobile, the cross-members are attached to the longitudinal rails and there are typically gaps between the cross-member and the longitudinal rail. In addition, the gap size can vary over the extent of the joint and thus, the gap cannot be filled with a uniform solid filler piece. In addition, most compatible metal fillers are too rigid to elastically deform and too strong to deform plastically under normal clamping loads to fill the gap in an appropriate manner.